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Biomedical subjects

H D Becker

Publications and source records attributed to H D Becker.

At least 73 records · Page 4Linked to original sources
PubMed2000

Postoperative colonic motility and tone in patients after colorectal surgery.

PURPOSE: Colonic motility is crucial for the resolution of postoperative ileus. However, few data are available on postoperative colonic motility and no data on postoperative colonic tone. We aimed to characterize postoperative colonic tone and motility in patients. METHODS: Nineteen patients were investigated with combined barostat and manometry recordings after left colonic surgery. During surgery a combined recording catheter was placed in the colon with two barostat bags and four manometry channels cephalad to the anastomosis. Recordings were performed twice daily from Day 1 to Day 3 after surgery. RESULTS: Manometry showed an increasing colonic motility index, which was a mean (+/- standard error of the mean) of 37 +/- 5 mmHg/minute on Day 1, 87 +/- 19 mmHg/minute on Day 2, and 102 +/- 13 mmHg/minute on Day 3 (P < 0.05 for Day 1 vs. Day 2 and Day 2 vs. Day 3). Low barostat bag volumes indicating a high colonic tone were observed on Day 1 after surgery and increased subsequently (barostat bag I was 19 +/- 4, 32 +/- 6, and 32 +/- 6 ml; barostat bag II was 13 +/- 1, 19 +/- 3, and 22 +/- 5 ml on Days 1, 2, and 3, respectively; for both barostat bags P < 0.05 for Day 1 vs. Day 2 but not Day 2 vs. Day 3). CONCLUSIONS: Colonic motility increased during the postoperative course. The low barostat bag volumes indicated a high colonic tone postoperatively which would correspond to a contracted rather than to a distended colon. High colonic tone postoperatively may be relevant for pharmacologic treatment of postoperative ileus.

Adult↗
PubMed2000

[Benign bile duct stenoses. Treatment with flexible metal wire stent or silicone prostheses (Yamakava) in nonresectable stenoses or high surgical risk cases].

INTRODUCTION: High benign biliary stenoses, which can occur as a complication of disease or surgery, may be difficult to correct by open surgery and may also carry a high risk. An alternative to surgery is the percutaneous implantation of a flexible metallic stent or silicon prosthesis at the affected site. METHODS: Twelve patients with benign biliary stenoses have been operated on in our department since March 1992, and the therapeutic success was reviewed in this study. RESULTS: Six received a Palmaz stent and six a silicon prosthesis, with a follow-up after completion of treatment of more than 7 years and more than 3 years, respectively. Fifty percent of the patients with a stent experienced no problems and 66% of the stents remained patent (including one requiring operative intervention to restore patency). No further surgery was necessary in any of the patients with a silicon prosthesis. CONCLUSION: When the advantages and disadvantages of the various procedures are considered, long-term splinting with a wide-lumened silicon prosthesis (Yamakava) appears to be a promising alternative to surgery for the treatment of benign biliary stenosis.

Adult↗
PubMed2000

RANTES in the postoperative course after liver transplantation.

RANTES (regulated upon activation, normal T-cell expressed and secreted), an inflammatory cytokine, promotes accumulation and activation of leukocytes. In 67 liver transplantations, systemic concentrations of RANTES were correlated to graft survival and incidence of rejection. RANTES levels either increased to highly elevated levels at day 14 (84 +/- 64 ng/ml; group 1; n = 43) or remained within the limit of healthy controls (19 +/- 11 ng/ml at day 14; group 2; n = 24). The 100-day graft function rate was 0.91 in group 1 and 0.63 in group 2 (P = 0.002). The risk ratio for rejection during the first 100 days was increased 2.2-fold in group 2 compared to group 1 (P = 0.02). High postoperative release of RANTES after liver transplantation, a beneficial factor, may reflect a general systemic immunological activation. It can be concluded that high early systemic RANTES levels may play a role in immunological recognition leading to a tolerance of the liver graft.

Adolescent↗
PubMed2000

Sphincter-saving treatment in epidermoid anal cancer: cooperative analysis of 142 patients in five German university surgical centers.

Five southern German university centers cooperated in comparing the effect of surgical vs. nonsurgical therapy strategies on survival and sphincter preservation in the treatment of anal cancer. A standardized questionnaire was used to evaluate retrospectively (mean follow-up 30 months) treatment strategy and outcome (survival, colostomy rate, colostomy-free survival) in patients treated between 1987 and 1996. Of the 142 patients 65% had squamous cell, 20% basaloid, 6% adeno-, and 1% undifferentiated carcinoma (8% histology not recorded); 9% were classified in UICC stage I, 37% in stage II, 25% in stage III, and 4% in stage IV (25% not recorded). Primary treatment consisted of local excision (10%), excision plus radio- and/or chemotherapy (17%), radiotherapy (20%), radiochemotherapy (28%), or colostomy with or without resection, radiotherapy, and chemotherapy (23%). We observed no difference between these treatment groups in overall (P = 0.43) or colostomy-free survival (P = 0.14, log-rank). Primary colostomy was prevented in 77% of cases and decreased over the years. Mean overall survival (in months) was 42 in stage I, 38 in stage II, and 25 in stage III (P = 0.0013); mean colostomy-free survival was 36 in stage I, 26 in stage II, and 16 in stage III (P = 0.0021, log-rank). Outcome was not significantly related to therapeutic strategy (surgery or radio-chemotherapy. Primary surgical and nonsurgical strategies in treating anal cancer thus produced similar results, although radiochemotherapy is usually recommended for sphincter-endangering anal cancer. Challenges to be met in the future include the prevention of metastasis and long-term preservation of anal sphincter function.

Adenocarcinoma↗
PubMed2000

Surgical management of peptic ulcer disease today--indication, technique and outcome.

AIMS: The current surgical management of peptic ulcer disease and its outcome have been reviewed. RESULTS: Today, surgery for peptic ulcer disease is largely restricted to the treatment of complications. In peptic ulcer perforation, a conservative treatment trial can be given in selected cases. If laparotomy is necessary, simple closure is sufficient in the large majority of cases, and definitive ulcer surgery to reduce gastric acid secretion is no longer justified in these patients. Laparoscopic surgery for perforated peptic ulcer has failed to prove to be a significant advantage over open surgery. In bleeding peptic ulcers, definitive hemostasis can be achieved by endoscopic treatment in more than 90% of cases. In 1-2% of cases, immediate emergency surgery is necessary. Some ulcers have a high risk of re-bleeding, and early elective surgery might be advisable. Surgical bleeding control can be achieved by direct suture and extraluminal ligation of the gastroduodenal artery or by gastric resection. Benign gastric outlet obstruction can be controlled by endoscopic balloon dilatation in 70% of cases, but gastrojejunostomy or gastric resection are necessary in about 30% of cases. CONCLUSIONS: Elective surgery for peptic ulcer disease has been largely abandoned, and bleeding or obstructing ulcers can be managed safely by endoscopic treatment in most cases. However, surgeons will continue to encounter patients with peptic ulcer disease for emergency surgery. Currently, laparoscopic surgery has no proven advantage in peptic ulcer surgery.

Humans↗
PubMed2000

The adaptor hypothesis revisited.

As originally postulated in Crick's Adaptor hypothesis, the faithful synthesis of proteins from messenger RNA is dependent on the presence of perfectly acylated tRNAs. The hypothesis also suggested that each aminoacyl-tRNA would be made by a unique enzyme. Recent data have now forced a revision of this latter point, with an increasingly diverse array of enzymes and pathways being implicated in aminoacyl-tRNA synthesis. These unexpected findings have far-reaching implications for our understanding of protein synthesis and its origins.

Amino Acyl-tRNA Synthetases↗
PubMed2000

Intermittent capnography during high-frequency jet ventilation for prolonged rigid bronchoscopy.

BACKGROUND: Gas exchange during high-frequency jet ventilation (HFJV) for prolonged rigid bronchoscopy (RBS) is usually monitored by arterial blood gas analysis. Capnography of expired gases during brief HFJV discontinuation may be a reliable and noninvasive supplemental method. Capnography can be performed either for single breaths or with respiratory rate (RR) reduced to 10 x min(-1). The aim of this study was to demonstrate that capnography during short periods of HFJV discontinuation represents a reliable measure of PaCO2 during prolonged RBS. METHODS: We prospectively investigated 100 consecutive patients (75 male and 25 female) undergoing HFJV for RBS. HFJV was delivered through the rigid bronchoscope at the following settings: working pressure 1.2 bar, rate 100 x min(-1), FIO2 0.99, t(i)/t(tot)0.6. The light guiding channel ending at the distal tip of the rigid bronchoscope was used for gas sampling. Capnograms were assessed at 5 min intervals and compared to PaCO2 from arterial blood samples drawn simultaneously. The accuracy of single breath CO2 sampling was compared with sampling at RR=10 x min(-1). RESULTS: Mean duration of RBS was 30+/-21 min. A significant correlation between capnography (PetCO2) and arterial blood gas analysis (PaCO2) was observed, being r=0.90 for the RR= 10 x min(-1) method and r=0.91 for the single breath method. Mean difference between PaCO2 and PetCO2 was 0.37+/-0.2 kPa throughout the entire study period. No significant differences between single breath sampling or sampling at RR=10 x min(-1) were observed. CONCLUSION: Capnography performed during short periods of HFJV discontinuation reliably and noninvasively reflects PaCO2 during prolonged endoscopic procedures. Capnography during HFJV for RBS may reduce the frequency of arterial blood gas sampling, the duration of unmonitored intervals and costs.

Adult↗
PubMed2000

Influence of airway-occluding instruments on airway pressure during jet ventilation for rigid bronchoscopy.

We measured changes in airway pressure (Paw) caused by microsurgical instruments introduced into a rigid bronchoscope during high frequency jet ventilation (HFJV). With approval of the institutional Ethics Committee, 10 adults undergoing elective tracheobronchial endoscopy and endosonography during general anaesthesia were investigated. Inflation of an endosonography probe balloon in the left main stem bronchus caused airway obstruction. Pressure measurements proximal and distal to the obstruction were compared after three degrees of obstruction (0%, 50% and 90%) and with two different driving pressure settings. Airway obstruction increased the mean (SD) peak inspiratory pressure (PIP) from 7.5 (2.6) to 9.5 (3.5) mm Hg for 2 atm (P = 0.0008) and from 9.7 (3.7) to 13.0 (5.1) mm Hg for 3 atm (P = 0.0001). Airway obstruction did not alter peripheral PIP (7.2 (4.1) to 7.1 (3.7) mm Hg for 2 atm and 8.8 (4.3) to 9.4 (5.2) mm for 3 atm), but resulted in an end-expiratory pressure (EEP) beyond the narrowing being significantly greater than in the unobstructed airway (2.5 (3.4) to 5.5 (3.7) mm Hg for 2 atm; P = 0.0005) and 3.2 (3.6) to 8.0 (4.3) mm for 3 atm; P < 0.0001). Severe airway narrowing increases inspiratory pressure proximal and expiratory pressure distal to the obstruction in relation to the applied driving pressure. Since the distal EEP never exceeded PIP, even near-total airway obstruction should not cause severe lung distension or barotrauma in subjects with normal lungs.

Aged↗
PubMed2000

Telediagnosis of transbronchial fine needle aspirations--a feasibility study.

AIM: To analyze the diagnostic accuracy of telediagnostic procedures for transbronchial fine needle aspirations. MATERIAL AND METHODS: A double blind study was performed on cytological slides of 54 randomly selected cases with transbronchial fine needle aspirations. The slides were digitized using a Leica digital camera DC100 mounted on a microscope Leica Laborlux S, and analyzed by an experienced pathologist without knowing the definite diagnosis or any additional clinical data. The diagnoses stated by analyzing the digital images were compared to the final conventional diagnoses. In addition, the duration of the digital diagnosis, used magnifications, and difficulties for correct sampling were documented. RESULTS: The "digital" diagnoses of the 54 cases were all in general agreement with the definite diagnoses. No wrong positive or wrong negative case in respect to malignant/non-malignant (31/23) or to small cell/non-small cell (9/22) occurred. The performance of a digital diagnosis lasted for 115 s at average (15-260 s), and is significantly longer compared to that of conventional fine needle aspiration judgement (20 s). The screening magnification was commonly set to x2.5, that for definite diagnostic analysis x40. Benign diseases (2 tuberculosis and 3 sarcoidosis cases) were correctly classified. CONCLUSIONS: Telepathology systems can probably be used for fine needle aspiration analysis without major diagnostic errors. Their use can improve the endoscopic sampling and avoid second anesthesia when missing the lesion of request during the first examination.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2000

The postoperative course of gamma-glutamyl transpeptidase--a marker of cytomegalovirus (CMV) replication risk?

Cytomegalovirus (CMV) infection is a common complication in the postoperative course of liver transplantation. In order to start early prophylactic therapy, but to avoid unnecessary treatment, or expensive screening, a desirable goal in post-transplant monitoring is to find appropriate markers in standard laboratory diagnostics. In the present study, the results of a 6-week CMV replication monitoring schedule by the pp65 antigenemia assay in 100 liver graft recipients were included. The activities of transaminases, glutamate dehydrogenase and gamma-glutamyl transpeptidase (gamma-GT) were measured by routine laboratory methods. In contrast to the transaminases, the serum activity of gamma-GT increased during the first postoperative week. The maximum levels were 246 +/- 211 U/l in patients without (n = 46) and 140 +/- 89 U/l in patients with early CMV replication (n = 54; p = 0.02). Patients with gamma-GT levels below 200 U/l on the 5th postoperative day (n = 72) had a CMV replication risk of 65%, whereas those patients with gamma-GT levels above this threshold had a risk of 30% (n = 28; p = 0.0007; relative risk = 2.9). These findings provide a routinely usable marker for the identification of patients at an increased risk of CMV replication. It can be considered that these phenomena may be caused by an additional immunosuppressive effect of the CMV virus.

Biomarkers↗
PubMed2000

[Possibilities of demonstration of growth factors in chronic wounds. Demonstration of RNA and protein in wound tissue].

Growth factors are important modulators of wound healing. So far, there is little clinical data showing that healing defects in chronic wounds are attribute to deficiency of growth factor expression. Characterization of growth factor expression is necessary to provide new directions toward developing therapies in treating wounds. Present available molecular and immunological techniques allow the analysis of mRNA and protein expression in small amounts of wound material. We analyzed growth factor expression in wound tissue and wound fluid from acute and secondary healing wounds. Wound tissue of secondary healing wounds reveals a higher mRNA growth factor expression compared to acute wound tissue. Secondary healing wounds from our studies demonstrated no deficiency of growth factor expression however, functional analysis may be necessary to determine their activity.

Endothelial Growth Factors↗
PubMed1999

C-fos protein expression in the nucleus of the solitary tract correlates with cholecystokinin dose injected and food intake in rats.

C-fos protein expression was investigated in the nucleus of the solitary tract (NTS) in response to increasing cholecystokinin (CCK) doses and food intake in rats by counting the number of c-fos protein positive cells in the NTS. C-fos protein expression in the NTS dose-dependently increased in response to CCK, the lowest effective dose being 0.1 microg/kg. The ED(50) for c-fos protein expression in the NTS in response to CCK was calculated to be 0.5 to 1.8 microg/kg, depending on the anatomical level of the NTS investigated. Food intake increased c-fos protein expression in the NTS, the maximum number of c-fos protein positive cells being reached at 90 min after the start of food intake. Regression analysis identified a positive correlation between c-fos protein expression and the amount of food intake. Our data indicate that subpopulations of the NTS that are activated by CCK or food intake are involved into the short-term regulation of food intake and the neural control of feeding by the caudal brainstem.

Animals↗
PubMed1999

[Diagnosis and therapy of tumor of Vater's ampulla].

BACKGROUND AND OBJECTIVE: Complete removal of tumours of the ampulla (papilla) of Vater is generally recommended, because of the known adenoma-carcinoma sequence yet the uncertainty regarding diagnosis of dignity of such tumours. The aim of this study was tho analyse different treatment concepts on the basis of data from a personal series of cases. PATIENTS AND METHODS: Clinical, laboratory and histological data as well as treatment and course in nine patients (three women, six men; mean age 62 [46-82] years) with ampulla of Vater adenoma, treated at one hospital, were analysed retrospectively. The patients had been followed for 6-36 months. RESULTS: All tumours had been removed endoscopically. Partial duodenopancreatectomy had subsequently been performed in two patients because of severe dysplasia. One tumour with moderately severe dysplasia had recurred locally within two months of endoscopic removal and was resected transduodenally. There had been no further recurrences 3 to 36 months later. CONCLUSION: If there is no evidence of malignity and frequent follow-up can be ensured, endoscopic removal of a tumour of the ampulla of Vater is justified. Otherwise transduodenal excision of the ampulla or partial duodenopancreatectomy should be undertaken.

Adenoma↗
PubMed1999

[The wound care center in surgery: an interdisciplinary concept for diagnostic and treatment of chronic wounds].

In Germany there is no standardized wound care for patients with chronic wounds in specialized centers. We have established a wound care unit for the past 6 years. The principal concept of therapy was characterized by standardized local surgery, moist wound dressings and concomitant treatment of the underlying disease. We performed local therapy, coordinated the interdisciplinary treatment and developed a new wound documentation system for quality control. We established a close network, integrating general practitioners and home care organizations to realize a mainly outpatient treatment supported by short hospital therapy. Exclusive outpatient treatment was performed in 42% of all patients. According to our prospective data, we achieved an improvement in wound care: 69% of the wounds resistant to therapy for a mean of 30 months healed within 12 months after therapy according to our protocol. Our data strongly supported the importance of local surgery: neither wound depth nor wound infection had any influence on the healing rate, presumably due to radical excisional debridement of necrotic tissue. The presented data justify on medical and economic grounds the establishment of such wound care centers in Germany.

Ambulatory Care↗
PubMed1999

[Immune regulation of wound healing].

Wound healing is a complex cascade of biochemical and cellular events designed to achieve restoration of tissue integrity following injury. Immune cells are critical for the outcome of healing. Much has been learned about the individual events that are involved in this process. Knowledge is scant, however, about the spatial and temporal interweaving of these events and how one step sets the stage for subsequent observed phenomena. Imbalance of stimulating and inhibiting factors causes failure of healing. Immunosuppressive states interfere with a normal immune response and impair wound repair. Clinically, new therapeutic approaches to modulate impaired healing are based on a knowledge of immune regulation of wound healing.

Animals↗
PubMed1999

Introducing fluorine-18 fluoromisonidazole positron emission tomography for the localisation and quantification of pig liver hypoxia.

Fluorine-18 labelled fluoromisonidazole ([18F]FMISO) has been shown to accumulate in hypoxic tissue in inverse proportion to tissue oxygenation. In order to evaluate the potential of [18F]FMISO as a possible positron emission tomography (PET) tracer for imaging of liver tissue hypoxia, we measured the [18F]FMISO uptake in 13 domestic pigs using dynamic PET scanning. Hypoxia was induced by segmental arterial hepatic occlusion. During the experimental procedure the fractional concentration of inspired oxygen (FiO2) was set to 0.67 in group A (n=6) and to 0.21 in group B (n=7) animals. Before and after arterial occlusion, the partial pressure of O2 in tissue (TPO2) and the arterial blood flow were determined in normal flow and flow-impaired liver segments. Standardised uptake values [SUV=kBq tissue (in g) / body weight (in kg) x injected dose (in kBq)] for [18F]FMISO were calculated from PET images obtained 3 hours after injection of about 10 MBq/kg body weight [18F]FMISO. Immediately before PET scanning, the mean arterial blood flow was significantly decreased in arterially occluded segments [group A: 0. 41 (0.32-0.52); group B: 0.24 (0.16-0.33) ml min-1 g-1] compared with normal flow segments [group A: 1.05 (0.76-1.46); group B: 1.14 (0.83-1.57) ml min-1 g-1; geometric mean (95% confidence limits); P<0.001 for both groups]. After PET scanning, the TPO2 of occluded segments (group A: 5.1 (4.1-6.4); group B: 3.5 (2.6-4.9) mmHg] was significantly decreased compared with normal flow segments [group A: 26.4 (21.2-33.0); group B: 18.2 (13.3-25.1) mmHg; P<0.001 for both groups]. During the 3-h PET scan, the mean [18F]FMISO SUV determined in occluded segments increased significantly to 3.84 (3.12-4.72) in group A and 5.7 (4.71-6.9) in group B, while the SUV remained unchanged in corresponding normal liver tissue [group A: 1.4 (1.14-1. 71); group B: 1.31 (1.09-1.57); P<0.001 for both groups]. Regardless of ventilation conditions, a significant inverse exponential relationship was found between the TPO2 and the [18F]FMISO SUV (r2=0. 88, P<0.001). Our results suggest that because tracer delivery to hypoxic tissues was maintained by the portal circulation, the [18F]FMISO accumulation in the liver was found to be directly related to the severity of tissue hypoxia. Thus, [18F]FMISO PET allows in vivo quantification of pig liver hypoxia using simple SUV analysis as long as tracer delivery is not critically reduced.

Animals↗
PubMed1999

Allogenic bone graft viability after hip revision arthroplasty assessed by dynamic [18F]fluoride ion positron emission tomography.

The biological fate of allogenic bone grafts in the acetabular cavity and their metabolic activity after acetabular augmentation is uncertain but is most important for the stability of hip implants after hip revision arthroplasty. The aim of this study was to quantify regional bone metabolism after hip replacement operations. Dynamic [18F]fluoride ion positron emission tomography (PET) was used to investigate the metabolic activity of acetabular allogenic bone grafts and genuine bone, either 3-6 weeks (short-term group, n = 9) or 5 months to 9 years (long-term group, n = 10) after hip revision arthroplasty. Applying a three-compartment model, the fluoride influx constant was calculated from individually fitted rate constants (Knlf) and by Patlak graphical analysis (Kpat). The results were compared with genuine cancellous and cortical acetabular bone of contralateral hips without surgical trauma (n = 7). In genuine cortical bone, Knlf was significantly increased in short- (+140.9%) and long-term (+100.0%) groups compared with contralateral hips. Allogenic bone grafts were characterised by a significantly increased Knlf in the short-term group (+190.9%) compared with contralateral hips, but decreased almost to the baseline levels of contralateral hips (+45.5%) in the long-term. Values of Knlf cor-related with the rate constant K1 in genuine (r = 0.89, P<0.001) and allogenic bone regions (r = 0.79, P<0.001), indicating a coupling between bone blood flow and bone metabolism in genuine bone as well as allogenic bone grafts. Kpat values were highly correlated with Knlf measurements in all regions. In conclusion, [18F]fluoride ion PET revealed the presence of an increased host bone formation in allogenic bone grafts early after hip revision arthroplasty. In contrast to genuine cortical bone, allogenic bone graft metabolism decreased over time, possibly due to a reduced ability to respond to the same extent as genuine bone to elevated metabolic demands after surgery.

Aged↗